Optical fiber connectors are widely used in optical fiber communications. Precision of the optical fiber connector, especially the optical fiber hole of the optical fiber connector is critical for reducing light losses of the optical fiber. The precision of the optical fiber hole is usually determined by an optical fiber hole insert of a mold, which is used to form the optical fiber hole, as such the insert needs to be carefully measured, including the size and the coarseness thereof
Coordinate measurement instruments may include probe contact coordinate measurement instruments and optical non-contact coordinate measurement instruments, which are capable of performing coordinate measurements (usually three-dimensional measurements) of objects. Fixing apparatuses which are key components of the coordinate measurement instruments are used to fix the objects in position.
As shown in FIG. 6, a cylindrical shaped insert 30 for molding the optical fiber hole. Along the lengthwise direction of the insert 30 are three diametric steps. Diameters of the insert 30 decrease in steps from the distal end 31 to the end of the optical fiber hole mold portion 32. A length of the distal end 31 and length and diameter of each step of the optical fiber hole mold portion 32 need to be measured. However, as the entire insert 30 is cylindrical, it is difficult to position the insert 30. In addition, it is difficult to find a reference surface on the insert 30 for the coordinate measurements.
What is needed, therefore, are an apparatus for fixing an optical fiber hole insert in a coordinate measurement and a method for measuring the optical fiber hole insert.